Super Mario Bros. X

Super Mario Bros. X is an unlicensed freeware game based on the early Mario console games. The game's included world, which contains over 50 main levels, along with multiple bonus levels, copies elements from Super Mario Bros., Super Mario Bros. 2, Super Mario Bros. 3, Super Mario World, Zelda II: The Adventure of Link, and Metroid. The game is written in Visual Basic for the Windows platform.

The gameplay of Super Mario Bros. X is very similar to the games it was intended to emulate, there are however several new elements. Simultaneous two player co-op gameplay is one of the major features of this fan-game. During a two-player game, the screen will split and recombine as the players separate and come together. Other new gameplay elements are the ability to fly the Koopa Clown Car that Bowser used in Super Mario World, plus the Billy Gun, which shoots Bullet Bills when picked up, Toothy, a Piranha Plant that the player can wield, the Propeller Block, a block that allows players to fly in New Super Mario Bros. Wii, and five playable characters: Mario, Luigi, Toad, Princess Peach, and Link.